The Effect of Hierarchical Task Representations on Action Selection in Voluntary Task Switching

• Main Author: Weaver, Starla M
• Format: Dissertation
• Language: English
• Published: ProQuest Dissertations & Theses 01.01.2011
• Subjects: Behavioral psychology; Cognitive psychology; Occupational psychology
• ISBN: 9781124962450; 112496245X

Actions can be represented at multiple levels. One can view an act as an isolated task or as part of a larger goal. The specific level at which one represents an action has the potential to influence how that action is performed. The current study explored the potential for hierarchical representations to also influence action selection within multitasking environments. The current study used the voluntary task switching paradigm to assess whether or not and under what conditions hierarchical task representations can be found within the free choice multitasking environments. In Experiment 1 participants switched between four individual task elements. Three manipulations of increasing complexity were used to encourage participants to represent these task elements hierarchically. While manipulations that took place only during the practice phase of the experiment were ineffective at establishing a hierarchical task representation, manipulations that persisted throughout the experiment influenced task selection. The results suggest that hierarchical representations had been formed. Experiment 2 explored the stability of hierarchical representations. The results suggest that, once established, the influences of hierarchical representations tend to persist, regardless of whether or not they are strictly required. A final experiment assessed the manner in which hierarchical representations are activated. A null result suggested that under the current experimental conditions all of the task elements that make up a hierarchical representation were not activated in unison. The current findings suggest that when actions are represented hierarchically, task elements that are part of the same aggregate task as the task performed on the previous trial will be prioritized for selection. This prioritization increases the probability that tasks that are part of the same hierarchical representation will be performed in succession and can speed the task selection process. As a result, hierarchical representations are likely to influence both task choice and performance speed, but influences on measures of task choice are likely to occur sooner than influences on performance. I propose that the more immediate influence of hierarchical representations on task choice reflects the functional role that hierarchical representations play in the action selection.